The absence of a front-view photo of the V6-powered C33 makes it difficult to compare with the other revealed 2014 cars, including the 'anteater'-nosed Williams, the 'nostriled' McLaren, the 'vacuum-cleaner' Ferrari and the 'tweezer'-nosed Lotus.

The Sauber C33

Photo by: Sauber F1 Team

The Lotus has caused the bigger stir so far, as the two tuning fork-like nose tips are actually different lengths, according to Germany's Auto Motor und Sport.

"In fact, the asymmetry is just a trick for the regulations," correspondent Michael Schmidt said. "Tips of equal length would make the E22 illegal," he added, explaining that the entire crash structure is probably inside the right-hand tip.

"Whether the FIA is happy with this solution is another matter," said Schmidt.

Still to be seen are the new Red Bull and Mercedes cars, but Nico Rosberg has at least driven the latter, when he ran the silver W05 at Silverstone last week.

"It looks quick," said the German, "but I don't know if it is quick yet!"

The first winter test kicks off on Tuesday, when rain is forecast at Jerez in Spain.

Rosberg will be wearing a new blue helmet in 2014, after his traditional yellow unpopularly clashed with teammate Lewis Hamilton's last season.